Display device including sealant and manufacturing method thereof

ABSTRACT

A display device includes a lower substrate; an upper substrate facing the lower substrate; a display element layer in a display area of the lower substrate and including a thin film transistor; and a sealing body in a peripheral area surrounding the display area, having a closed curve shape, and between the lower substrate and the upper substrate, in which the sealing body includes a first portion and a second portion, the first portion and the second portion respectively extending along different directions from each other, and the first portion and the second portion respectively have different deposition structures from each other.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2013-0105392, filed in the Korean IntellectualProperty Office on Sep. 3, 2013, the entire contents of which areincorporated herein by reference.

BACKGROUND

1. Field

The present invention relates generally to a display device including asealant and a manufacturing method thereof, and more particularly, to adisplay device and a manufacturing method thereof capable of reducing orpreventing a Newton's ring phenomenon.

2. Description of the Related Art

A display device, such as a liquid crystal display (LCD), an organiclight emitting diode (OLED) display, and an electrophoretic display,includes a field generating electrode and an electro-optical activelayer. For example, the organic light emitting diode (OLED) displayincludes an organic light emitting layer as the electro-optical activelayer. The field generating electrode is connected to a switchingelement, such as a thin film transistor, to receive a data signal, andthe electro-optical active layer converts the data signal to an opticalsignal to display an image.

Among the display devices, because the organic light emitting diode(OLED) display, as a self-light emitting display, does not require aseparate light source, its characteristics, in terms of powerconsumption, response speed, viewing angle, and contrast ratio, areexcellent.

The organic light emitting diode (OLED) display may include a pluralityof pixels such as red pixels, blue pixels, green pixels, or whitepixels, and may express a full range of colors by combining the pixels.Each pixel includes an organic light emitting element and a plurality ofthin film transistors for driving the organic light emitting element.

The light emitting element of the organic light emitting diode (OLED)display includes a pixel electrode, an opposed electrode, and a lightemitting layer positioned between the two electrodes. One of the pixelelectrode and the opposed electrode becomes an anode, and the otherelectrode becomes a cathode. An electron injected from the cathode and ahole injected from the anode are coupled with each other in the lightemitting layer to form an exciton, and the exciton emits light whiledischarging energy. The opposed electrode is formed throughout aplurality of pixels to transfer a common voltage (e.g., a predeterminedcommon voltage).

In a display device, in addition to the organic light emitting diode(OLED) display, when impurities such as moisture or oxygen flow orpenetrate into the display device from an ambient environment,oxidization, exfoliation, and the like of the electrode may occur, andas a result, a lifespan of the device may be shortened or light emissionefficiency may deteriorate, and effects such as deformation of anemitted color may occur.

Accordingly, when the display device is manufactured, sealing isperformed so that an internal element is separated or protected from theoutside to prevent impurities, such as moisture, from penetratingtherein. The sealing method, in the case of the organic light emittingdiode (OLED) display, may include, for example, a method of laminating alayer made of organic polymer such as polyester (PET) on a completedlower substrate, a method of forming a cover or a cap on anencapsulation substrate and sealing an edge of a cover substrate with asealant, or the like. A frit having excellent moisture preventioncharacteristics may be included in the sealant, and an organic sealantand moisture absorbent may also be utilized.

The above information disclosed in this Background section is only forenhancement of understanding of the background of the invention andtherefore it may contain information that does not form the prior artthat is already known in this country to a person of ordinary skill inthe art.

SUMMARY

In the display device including the sealant, when a distance between thelower substrate and the encapsulation substrate is not regular, lightincident from the outside causes an optical interference phenomenon thatgenerates a concentric circular pattern at a contact point between theencapsulation substrate and the lower substrate. Such a concentriccircular pattern is called a Newton's ring. For example, when thesealant includes the frit, the lower substrate and the encapsulationsubstrate are bonded to each other and then adhered to each other byapplying heat to the sealant, and in this case, according to theapplication of heat, a thickness of the sealant may vary according to aposition around the display device. In this case, the distance betweenthe lower substrate and the encapsulation substrate is not regular andthus the Newton's ring may be generated. The Newton's ring maynegatively affect visibility during driving of the display device andimage quality.

Accordingly, aspects of embodiments of the present invention aredirected toward a display device and a manufacturing method thereofhaving enhanced image quality by preventing or reducing a Newton's ringphenomenon.

According to an example embodiment of the present invention, a displaydevice includes a lower substrate; an upper substrate facing the lowersubstrate; a display element layer in a display area of the lowersubstrate and including a thin film transistor; and a sealing body in aperipheral area surrounding the display area, having a closed curveshape, and between the lower substrate and the upper substrate, in whichthe sealing body includes a first portion and a second portion, thefirst portion and the second portion respectively extending in differentdirections from each other, and the first portion and the second portionrespectively have different deposition structures from each other.

The sealing body may include a sealant coupling the lower substrate andthe upper substrate, and the sealant included in the first portion andthe sealant included in the second portion may be different in heightfrom each other.

The first portion may include a first pattern and the second portion maynot include the first pattern.

The first pattern may include a pattern that is at least one layer ofthe display element layer.

The first pattern may include a layer that is at least one of aconductive layer, a semiconductor layer, and an insulating layer, andthe conductive layer, the semiconductor layer, and the insulating layermay be in the display element layer.

The sealant at the first portion may be less in height than that of thesealant at the second portion.

The first portion and the second portion may each further include asecond pattern including a metal.

The sealant may include a frit.

A peripheral insulating layer may be between the sealant and the lowersubstrate, in which the peripheral insulating layer may be at least oneinsulating layer of the display element layer, and the first pattern mayinclude an opening in the peripheral insulating layer.

According to another example embodiment of the present invention, amanufacturing method of a display device includes providing a lowersubstrate and an upper substrate that include a display area and aperipheral area around the display area; and forming a sealing bodybetween the lower substrate and the upper substrate, the sealing bodyhaving a closed curve shape surrounding the display area and positionedin the peripheral area, in which the sealing body includes a firstportion and a second portion, the first portion and the second portionrespectively extending along different directions from each other, andthe first portion and the second portion respectively have differentdeposition structures from each other.

The forming of the sealing body may include coating a sealant to couplethe lower substrate and the upper substrate with each other on the lowersubstrate or the upper substrate, and curing the sealant, in which thecured sealant at the first portion and the cured sealant at the secondportion may be different in height from each other.

The forming of the sealing body may also include forming a first patternin the first portion but not in the second portion.

The manufacturing method of a display device may also include forming adisplay element layer including a thin film transistor in the displayarea of the lower substrate, in which the first pattern may be formedutilizing a same process as at least one layer of the display elementlayer.

The first pattern may include a layer that is at least one of aconductive layer, a semiconductor layer, and an insulating layer, andthe conductive layer, the semiconductor layer, and the insulating layerare in the display element layer.

After the curing of the sealant, the sealant at the first portion may beless in height than that of the sealant at the second portion.

The forming of the display element layer may include forming aperipheral insulating layer between the sealant and the lower substrate,the peripheral insulating layer may be at least one insulating layer ofthe display element layer, and the first pattern may have an opening inthe peripheral insulating layer.

The first pattern may be formed when the at least one insulating layerof the display element layer is patterned.

The sealant may include a frit.

According to aspects of the example embodiment of the present invention,it is possible to enhance image quality by preventing a Newton's ringphenomenon.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a display device according to an exampleembodiment of the present invention,

FIG. 2 is a schematic circuit diagram of one pixel of the display deviceaccording to the example embodiment of the present invention,

FIG. 3 is a layout view of one pixel of the display device according tothe example embodiment of the present invention,

FIG. 4 is a cross-sectional view of the display device of FIG. 3 takenalong the line IV-IV,

FIG. 5 is a plan view of a sealing body of the display device accordingto the example embodiment of the present invention,

FIGS. 6 to 11 are cross-sectional views of one edge of the displaydevice according to the example embodiment of the present invention,respectively,

FIG. 12 is a plan view of a sealing body of the display device accordingto an example embodiment of the present invention,

FIG. 13 is a cross-sectional view of one edge of the display deviceaccording to another example embodiment of the present invention,

FIGS. 14 to 20 are cross-sectional views illustrating intermediate actsof a manufacturing method of a display device according to an exampleembodiment of the present invention, and

FIGS. 21 to 24 are cross-sectional views illustrating intermediate actsof a manufacturing method of a display device according to an exampleembodiment of the present invention.

DETAILED DESCRIPTION

The present invention will be described more fully hereinafter withreference to the accompanying drawings, in which example embodiments ofthe invention are shown. As those skilled in the art would realize, thedescribed embodiments may be modified in various different ways, allwithout departing from the spirit or scope of the present invention.

In the drawings, the thickness of layers, films, panels, regions, etc.,may be exaggerated for clarity. Like reference numerals designate likeelements throughout the specification. It will be understood that whenan element such as a layer, film, region, or substrate is referred to asbeing “on” another element, it may be directly on the other element orintervening elements may also be present. In contrast, when an elementis referred to as being “directly on” another element, there are nointervening elements present. Expressions such as “at least one of,”when preceding a list of elements, modify the entire list of elementsand do not modify the individual elements of the list. As used herein,the term “and/or” includes any and all combinations of one or more ofthe associated listed items. Further, the use of “may” when describingembodiments of the present invention refers to “one or more embodimentsof the present invention.”

First, a display device according to an example embodiment of thepresent invention will be described with reference to FIGS. 1 to 4.

FIG. 1 is a plan view of a display device according to an exampleembodiment of the present invention, FIG. 2 is a schematic circuitdiagram of one pixel of the display device according to the exampleembodiment of the present invention, FIG. 3 is a layout view of onepixel of the display device according to the example embodiment of thepresent invention, and FIG. 4 is a cross-sectional view of the displaydevice of FIG. 3 taken along the line IV-IV.

First, referring to FIG. 1, a display panel 300 of a display deviceaccording to an example embodiment of the present invention includes adisplay area DA which is an area displaying an image (e.g., an areaconfigured to display an image), and a peripheral area PA therearoundwhen viewed from above. On the contrary, when viewed from across-sectional view, the display panel 300 of the display deviceaccording to the example embodiment of the present invention includes alower substrate 110 and an upper substrate 210 facing each other.

The display area DA includes a plurality of signal lines, and aplurality of pixels PX connected to the signal lines and arrangedsubstantially in a matrix form.

The signal lines may be provided on the lower substrate 110, and includea plurality of scanning signal lines G1-Gn transferring (e.g.,configured to transfer) scanning signals, and a plurality of data linesD1-Dm transferring (e.g., configured to transfer) data voltages. Thescanning signal lines G1-Gn extend substantially in a row direction andmay extend parallel to each other, and the data lines D1-Dm extendsubstantially in a column direction and may extend parallel to eachother.

Each pixel PX may include a switching element connected to at least oneof the scanning signal lines G1-Gn and at least one of the data linesD1-Dm, at least one pixel electrode connected to the switching element,and an opposed electrode forming an electro-optical active layer, suchas a light emitting element, together with the pixel electrode. In thecase of an organic light emitting diode (OLED) display, a light emittinglayer is positioned between the pixel electrode and the opposedelectrode to form a light emitting element. The switching element mayinclude at least one thin film transistor. The opposed electrode maytransfer (e.g., may apply) a common voltage.

In order to implement a color display, each pixel PX may display one ofthe primary colors, and a desired color may be recognized by combiningthe primary colors. An example of the primary colors may include threeprimary colors or four primary colors such as red, green, blue, or thelike. Each pixel PX may further include a color filter positioned at aspace corresponding to each pixel electrode and expressing one of theprimary colors, and the light emitting layer may be a color lightemitting layer.

Referring to FIG. 2, the display device according to the exampleembodiment of the present invention, that is, as an organic lightemitting diode (OLED) display, includes a plurality of signal lines 121,171, and 172, and a plurality of pixels PX connected thereto andarranged substantially in a matrix form.

The signal lines include a scanning signal line 121, a data line 171, aplurality of driving voltage lines 172 transferring (e.g., configured totransfer) driving voltages, and the like.

Each pixel PX includes a switching transistor Qs, a driving transistorQd, a storage capacitor Cst, and an organic light emitting element LD.

A control terminal of the switching transistor Qs is connected to thescanning signal line 121, an input terminal is connected to the dataline 171, and an output terminal is connected to the driving transistorQd. The switching transistor Qs transfers a data signal received fromthe data line 171 to the driving transistor Qd in response to a scanningsignal received from the scanning signal line 121.

A control terminal of the driving transistor Qd is connected to theswitching transistor Qs, an input terminal is connected to the drivingvoltage line 172, and an output terminal is connected to the organiclight emitting element LD. The driving transistor Qd allows an outputcurrent I_(LD) of varying size according to a voltage applied betweenthe control terminal and the output terminal to flow.

The capacitor Cst is connected between the control terminal and theinput terminal of the driving transistor Qd. The capacitor Cst charges adata voltage applied to the control terminal of the driving transistorQd and maintains the charged data voltage (signal) even after theswitching transistor Qs is turned off.

The organic light emitting element LD, for example, an organic lightemitting diode (OLED), includes an anode connected to the outputterminal of the driving transistor Qd and a cathode connected to acommon voltage Vss. The organic light emitting element LD emits light ofvarying intensity according to the output current I_(LD) of the drivingtransistor Qd to display an image.

The switching transistor Qs and the driving transistor Qd may ben-channel field effect transistors (FET), but at least one thereof maybe a p-channel field effect transistor.

However, a connection relationship of the transistors Qs and Qd, thecapacitor Cst, and the organic light emitting diode LD may be changed.

Referring to FIGS. 3 and 4, in a structure of the organic light emittingdiode (OLED) display according to the example embodiment of the presentinvention, a buffer layer 111 may be positioned on the lower substrate110 made of, for example, glass or plastic. The buffer layer 111 mayprevent impurities from penetrating therethrough, and a surface thereofmay be flat. The buffer layer 111 may include, for example, siliconnitride (e.g., SiN_(x)), silicon oxide (e.g., SiO₂), silicon oxynitride(e.g., SiO_(x)N_(y)), or the like. The buffer layer 111 may also beomitted.

A plurality of first semiconductors 154 a and a plurality of secondsemiconductors 154 b may be formed on the buffer layer 111. The firstsemiconductor 154 a may include a channel region, a source region at oneside of the channel region, and a drain region at another side of thechannel region, the source region and the drain region being suitablydoped, respectively. The second semiconductor 154 b may include achannel region 152 b, a source region 153 b at one side of the channelregion 152 b, and a drain region 155 b at another side of the channelregion 152 b, the source region 153 b and the drain region 155 b beingsuitably doped. The first semiconductor 154 a and the secondsemiconductor 154 b may include, for example, amorphous silicon,polysilicon, or oxide semiconductor.

A gate insulating layer 140 may be made of silicon nitride (e.g.,SiN_(x)), silicon oxide (e.g., SiO₂), or the like and may be positionedon the first semiconductor 154 a and the second semiconductor 154 b.

A plurality of scanning signal lines 121 including a first controlelectrode 124 a and a plurality of gate conductors including a secondcontrol electrode 124 b are formed on the gate insulating layer 140.

The gate lines 121 may transfer gate signals and extend mainly in ahorizontal direction. The first control electrode 124 a may extendupward from (e.g., perpendicular to) the scanning signal line 121. Thesecond control electrode 124 b may be separated from the scanning signalline 121. The second control electrode 124 b may include a storageelectrode elongated in a vertical direction. The first control electrode124 a may overlap with a part of the first semiconductor 154 a,particularly, the channel region 152 b, and the second control electrode124 b may be overlap with a part of the second semiconductor 154 b,particularly, the channel region 152 b.

A first passivation layer 180 a maybe positioned on the gate insulatinglayer 140 and the gate conductor. The first passivation layer 180 a andthe gate insulating layer 140 may include a contact hole 183 a exposingthe source region of the first semiconductor 154 a, and a contact hole185 a exposing the drain region of the first semiconductor 154 a, and acontact hole 183 b exposing the source region 153 b of the secondsemiconductor 154 b, and a contact hole 185 b exposing the drain region155 b of the second semiconductor 154 b. The first passivation layer 180a may include a contact hole 184 exposing the second control electrode124 b.

A plurality of data conductors including a plurality of data lines 171,a plurality of driving voltage lines 172, a plurality of first outputelectrodes 175 a, and a plurality of second output electrodes 175 b maybe formed on the first passivation layer 180 a.

The data lines 171 may mainly extend in a vertical direction to crossthe scanning signal lines 121. Each data line 171 may include aplurality of first input electrodes 173 a extending toward thecorresponding first control electrode 124 a.

The driving voltage line 172 transfers a driving voltage and mainlyextends in a vertical direction to cross the scanning signal line 121.Each driving voltage line 172 may include a plurality of second inputelectrodes 173 b which extend toward the corresponding second controlelectrode 124 b. In the case where the second control electrode 124 bincludes the storage electrode, the driving voltage line 172 may includea portion overlapped with the storage electrode.

The first and second output electrodes 175 a and 175 b may be separatedfrom each other to have island shapes and are separated from the dataline 171 and the driving voltage line 172. The first input electrode 173a and the first output electrode 175 a may face each other on the firstsemiconductor 154 a, and the second input electrode 173 b and the secondoutput electrode 175 b may face each other on the second semiconductor154 b.

The first input electrode 173 a and the first output electrode 175 a maybe connected to the source region and the drain region of the firstsemiconductor 154 a through the contact holes 183 a and 185 a,respectively. The first output electrode 175 a may be connected to thesecond control electrode 124 b through the contact hole 184. The secondinput electrode 173 b and the second output electrode 175 b may beconnected to the source region 153 b and the drain region 155 b of thesecond semiconductor 154 b through the contact holes 183 b and 185 b,respectively.

The first control electrode 124 a, the first input electrode 173 a, andthe first output electrode 175 a form the switching transistor Qstogether with the first semiconductor 154 a; and the second controlelectrode 124 b, the second input electrode 173 b, and the second outputelectrode 175 b form the driving transistor Qd together with the secondsemiconductor 154 b. The structure of each of the switching transistorQs and the driving transistor Qd is not limited thereto and may bevariously modified.

A second passivation layer 180 b made of, for example, an inorganicinsulator (such as silicon nitride or silicon oxide) may be positionedon the data conductor. The second passivation layer 180 b may have aflat surface by removing a step in order to increase light emissionefficiency of the organic light emitting element to be formed thereon.The second passivation layer 180 b may include a contact hole 185 cexposing the second output electrode 175 b.

A plurality of pixel electrodes 191 may be formed on the secondpassivation layer 180 b.

The pixel electrode 191 of each pixel PX may be physically andelectrically connected with the second output electrode 175 b throughthe contact hole 185 c of the second passivation layer 180 b. The pixelelectrode 191 may include, for example, a semi-transmissive conductivematerial or a reflective conductive material.

Referring to FIG. 4, a layer formed including a layer on the lowersubstrate 110, for example, the buffer layer 111 and layers up through alayer below the pixel electrode 191, for example, the second passivationlayer 180 b is called a transistor layer TFL.

A pixel defining layer 360 (e.g., a partition) having a plurality ofopenings exposing the pixel electrode 191 may be positioned on thesecond passivation layer 180 b. The openings of the pixel defining layer360 exposing the pixel electrode 191 may define each pixel area. Thepixel defining layer 360 may also be omitted.

A light emitting member 370 is positioned on the pixel defining layer360 and the pixel electrode 191. The light emitting member 370 mayinclude a first organic common layer 371, a plurality of light emittinglayers 373, and a second organic common layer 375 which are laminated(e.g., laminated in sequence).

The first organic common layer 371 may include, for example, at leastone of a hole injecting layer and a hole transport layer which arelaminated (e.g., laminated in sequence). The first organic common layer371 may be formed across the entire display area in which the pixels PXare disposed, and may also be formed only in each pixel PX area.

The light emitting layer 373 may be positioned on the pixel electrode191 of each corresponding pixel PX. The light emitting layer 373 may bemade of an organic material which emits light of one of the primarycolors such as red, green, or blue, and may have a structure in which aplurality of organic material layers emitting light of different colorsare laminated. For example, a red organic light emitting layer may belaminated on the first organic common layer 371 of a pixel PX displaying(e.g., configured to display) red, a green organic light emitting layermay be laminated on the first organic common layer 371 of a pixel PXdisplaying (e.g., configured to display) green, and a blue organic lightemitting layer may be laminated on the first organic common layer 371 ofa pixel PX displaying (e.g., configured to display) blue. However, thepresent invention is not limited thereto, and an organic light emittinglayer displaying one primary color may be laminated on the pixelsdisplaying different colors. According to another example embodiment ofthe present invention, the light emitting layer 373 may also include awhite light emitting layer displaying (e.g., configured to display)white.

The second organic common layer 375 may include, for example, at leastone of an electron transport layer and an electron injecting layer whichare laminated (e.g., laminated in sequence).

An opposed electrode 270 transferring a common voltage Vss may be formedon the light emitting member 370. The opposed electrode 270 may include,for example, a transparent conductive material. For example, the opposedelectrode 270 may be made of a transparent conductive material, orformed by thinly depositing a metal such as calcium (Ca), barium (Ba),magnesium (Mg), aluminum (Al), silver (Ag), or the like having a lighttransmitting characteristic.

The pixel electrode 191, the light emitting member 370, and the opposedelectrode 270 of each pixel PX form the light emitting element LD, andone of the pixel electrode 191 and the opposed electrode 270 is acathode and the other is an anode. Further, the storage electrode andthe driving voltage line 172 which are overlapped with each other mayform the storage capacitor Cst.

An upper substrate 210 (e.g., an encapsulation substrate) is positionedabove the opposed electrode 270. The upper substrate 210 encapsulatesthe light emitting member 370 and the opposed electrode 270, therebypreventing or reducing moisture and/or oxygen penetration from theoutside. A distance between the opposed electrode 270 and the uppersubstrate 210 may be regular (e.g., substantially constant or uniform),and a sealing body 310 may be positioned between the opposed electrode270 and the upper substrate 210.

Referring back to FIG. 1, the sealing body 310 may be positioned in theperipheral area PA where the lower substrate 110 and the upper substrate210 face each other. For example, the sealing body 310 may be formedaround the display area DA and may have a closed curve or rectangleshape. The sealing body 310 couples and fixes the lower substrate 110and the upper substrate 210 and prevents or reduces impurities (such asexternal moisture, oxygen, or the like) from penetrating to be betweenthe lower substrate 110 and the upper substrate 210 and encapsulates theelectro-optical active layer, such as the light emitting element. Inthis case, the upper substrate 210 (e.g., the encapsulation substrate)prevents or reduces the electro-optical active layer, such as the lightemitting element, from being exposed to external moisture or oxygen andprotects the electro-optical active layer so that a characteristicthereof is not changed.

The sealing body 310 may include a frit having excellent moistureresistance and may also include an organic sealant and moistureabsorbent. For example, the sealing body 310 may include a sealant whichis positioned between the lower substrate 110 and the upper substrate210 to couple (e.g., fuse) the lower substrate 110 and the uppersubstrate 210 by applying heat thereto. In this case, the heat may beapplied by using an infrared lamp, a laser, or the like. The sealant mayalso include a light absorbent material which may absorb a laser, aninfrared light, or the like. For example, the frit may generally use anoxide powder included in a glass powder and may include an organicmaterial so as to be a paste (e.g., in a paste-like state). When thefrit, coated between the lower substrate 110 and the upper substrate210, is melted or fired by applying the heat, the lower substrate 110and the upper substrate 210 may be bonded to each other through thefired frit, and internal elements of the display device may beencapsulated (e.g., completely encapsulated).

The sealing body 310 may include a plurality of portions extending indifferent directions, and in the example embodiment, respective to thedisplay area DA, a right portion 310 a is positioned at the right side,a left portion 310 b is positioned at the left side, an upper portion310 c is positioned at the upper side, and a lower portion 310 d ispositioned at the lower side. The right portion 310 a, the left portion310 b, the upper portion 310 c, and the lower portion 310 d of thesealing body 310 together form a closed curve or rectangle shape.

According to an example embodiment of the present invention, at leastone of the right portion 310 a, the left portion 310 b, the upperportion 310 c, and the lower portion 310 d of the sealing body 310 has adifferent deposition structure from at least one of the remainingportions. For example, in a manufacturing process of the display device,in the case where a thickness of the sealant according to a position onthe sealing body 310 is changed during a melting process of the sealantincluded in the sealing body 310, deposition structures of portions ofthe sealing body 310 may be different from each other at two portions ofthe sealing body 310 such that the corresponding sealants may havedifferent thicknesses. Accordingly, even under the condition in whichthe thickness of the sealant may vary during the manufacturing process,the thickness of the sealing body 310 itself may remain substantiallyuniform and thus the distance between the lower substrate 110 and theupper substrate 210 may be substantially uniform. As a result, theNewton's ring phenomenon generated when a deviation occurs in thedistance between the lower substrate 110 and the upper substrate 210,which are closely adjacent to each other may be prevented. A structureof the sealing body 310 will be described below in further detail.

The peripheral area PA may include a part of the lower substrate 110which is not covered by the upper substrate 210 but is exposed. A driver500 or a pad portion connected to the driver may be positioned on theexposed lower substrate 110. The driver 500 may include a scan drivertransferring scanning signals to the scanning signal lines G1-Gn, a datadriver transferring to data voltages to the data lines, or the like. Thedriver 500 may be directly installed on the lower substrate 110 in an ICchip form or installed on a flexible printed circuit film or a circuitboard and attached to the lower substrate 110 in a tape carrier package(TCP) form.

Next, the display device including the sealing body 310 according to theexample embodiment of the present invention will be described withreference to FIGS. 5 to 8 together with the drawings described above.

FIG. 5 is a plan view of a sealing body of the display device accordingto the example embodiment of the present invention, and FIGS. 6 to 8 arecross-sectional views of one edge of the display device according to theexample embodiment of the present invention, respectively.

Referring to FIG. 5, the sealing body 310 of the display deviceaccording to the example embodiment of the present invention includes asealant 311 which may fuse the lower substrate 110 and the uppersubstrate 210. The sealant 311 may include a frit.

At least one of the right portion 310 a, the left portion 310 b, theupper portion 310 c, and the lower portion 310 d of the sealing body 310may include a plurality of first patterns 312. The first pattern 312having an island shape may be positioned between the sealant 311 and thelower substrate 110 and may allow the sealant 311 to be cured well.

The first pattern 312 may include a conductive material such as a metaland may be formed as a single layer or a multi-layer structure. Thefirst pattern 312 may include the same layer as at least one conductivelayer including, for example, a metal of the transistor layer TFL of thethin film transistor of the display area DA and the pixel 191, and thefirst pattern 312 may be formed by the same process as the conductivelayer.

The first patterns 312 may be regularly disposed as illustrated in FIG.5, but may be irregularly disposed unlike this. Further, the shape ofthe first pattern 312 is not limited to a rectangle and may have variousshapes.

Referring to FIGS. 6 to 8, in the display area DA of the display deviceaccording to the example embodiment of the present invention, atransistor layer TFL including a transistor is positioned on the lowersubstrate 110, a plurality of pixel electrodes 191 are positionedthereon, and a pixel defining layer 360 positioned between adjacentpixels PX may be positioned thereon. A light emitting member and anopposed electrode on the pixel electrode 191 are omitted forconvenience. The transistor layer TFL may include a plurality ofconductive layers, an insulating layer, a semiconductor layer, and thelike as described above. For example, the transistor layer TFL may havethe same structure as the transistor layer TFL of the organic lightemitting diode (OLED) display according to the example embodimentillustrated in FIGS. 3 and 4, described above.

Many insulating layers including, for example, the transistor layer TFLmay be positioned even in the peripheral area PA.

The upper substrate 210 (e.g., the encapsulation substrate) may bepositioned on or above the lower substrate 110 with the transistor layerTFL and the like, and the lower substrate 110 and the upper substrate210 may be bonded to each other with the sealing body 310 therebetweenin the peripheral area PA. A distance D1 between the lower substrate 110and the upper substrate 210 in the display area DA may be, for example,approximately 6.2 μm, but is not limited thereto. Here, the distance D1between the lower substrate 110 and the upper substrate 210 in thedisplay area DA may be a distance between a top surface of the pluralityof layers formed on the lower substrate 110 and a bottom surface of theupper substrate 210.

A plurality of layers including the transistor layer TFL between thelower substrate 110 and the upper substrate 210 in the display area DAis called a display element layer.

As described above, at least one of the right portion 310 a, the leftportion 310 b, the upper portion 310 c, and the lower portion 310 d ofthe sealing body 310 may have a different deposition structure from atleast one of the remaining portions.

FIGS. 6 to 8 illustrate examples of deposition structures of the rightportion 310 a, the left portion 310 b, and the upper portion 310 c ofthe sealing body 310 in the peripheral area PA where the driver 500 isnot positioned, respectively. In the example embodiment, the depositionstructure of the right portion 310 a of the sealing body 310 may bedifferent from the deposition structures of the left portion 310 b andthe upper portion 310 c, and the deposition structures of the leftportion 310 b and the upper portion 310 c may be the same as each other.

Referring to FIG. 6, the right portion 310 a of the sealing body 310 mayinclude a sealant 311, a first pattern 312, and a second pattern 313.

The sealant 311 may include a frit and may bond the lower substrate 110and the upper substrate 210 to each other. At the right portion 310 a, aheight D2 of the sealant 311 may be less than the distance D1 betweenthe lower substrate 110 and the upper substrate 210 in the display areaDA.

The first pattern 312 and the second pattern 313 may be different layersand may be positioned below the sealant 311. As illustrated in FIG. 6,the second pattern 313 may be positioned below the first pattern 312 butmay be reversely positioned.

The first pattern 312 having an island shape may be positioned betweenthe sealant 311 and the lower substrate 110 and may include a conductivematerial such as a metal.

The second pattern 313 may be positioned between the sealant 311 and thelower substrate 110 and may be formed as a signal layer or a multi-layerstructure including at least one of a conductive material such as ametal, a semiconductor layer, or an organic or inorganic insulatingmaterial. The second pattern 313 may include the same material or layeras at least one of the layers between the lower substrate 110 and theupper substrate 210 in the display area DA, that is, at least one of theplurality of conductive layers of the display element layer includingthe transistor layer TFL with the thin film transistor, thesemiconductor layer, or the plurality of insulating layers, and may beformed by the same process as the layer.

For example, the second pattern 313 may be positioned on the same layeras the gate conductor and/or the gate insulating layer 140 and formed bythe same process, and the first pattern 312 may be positioned on thesame layer as the data conductor and formed by the same process.

A sum of a height D3 of the second pattern 313 and a height D2 of thesealant 311 may be substantially the same as the distance D1 between thelower substrate 110 and the upper substrate 210 in the display area DA.

Referring to FIGS. 7 and 8, the left portion 310 b and the upper portion310 c of the sealing body 310 may include the sealant 311 and have thesame structure as the right portion 310 a illustrated in FIG. 6 and thefirst pattern 312 and the second pattern 313 may not be included.

At the left portion 310 b and the upper portion 310 c of the sealingbody 310, a height D4 of the sealant 311 may be substantially the sameas the distance D1 between the lower substrate 110 and the uppersubstrate 210 in the display area DA.

As such, in the manufacturing process of the organic light emittingdiode (OLED) display, in the case where a difference or deviation inheight of the sealant 311 occurs, an additional second pattern 313described above may be further formed at a portion where the height ofthe sealant 311 is relatively small. As a result, the distance betweenthe lower substrate 110 and the upper substrate 210 may remainsubstantially uniformly, and generation of the Newton's ring may bereduced or prevented. In this case, the second pattern 313 may beconcurrently (e.g., simultaneously) formed when at least one of the manyconductive layers or many insulating layers of the display area DA isformed, and according to a desired or required thickness of the secondpattern 313, the second pattern 313 may be formed as a single layer or amulti-layer structure.

In the example embodiment illustrated in FIGS. 6 to 8, during thebonding process of the lower substrate 110 and the upper substrate 210,when the sealant 311 is melted by applying heat, such as by a laser, tothe sealant 311, as an example, the heights of the sealants 311 at theleft portion 310 b and the upper portion 310 c may be greater than theheight of the right portion 310 a of the sealing body 310.

Next, the display device including the sealing body 310 according toanother example embodiment of the present invention will be describedwith reference to FIGS. 9 to 12 together with the drawings describedabove. The same constituent elements as the example embodimentsdescribed above designate the same reference numerals, and theduplicated description will be omitted.

FIGS. 9 to 11 are cross-sectional views of one edge of the displaydevice according to the example embodiment of the present invention,respectively, and FIG. 12 is a plan view of a sealing body of thedisplay device according to the example embodiment of the presentinvention.

Referring to FIGS. 9 to 11, in the display area DA of the display deviceaccording to the example embodiment of the present invention, atransistor layer TFL including a transistor is positioned on the lowersubstrate 110, a plurality of pixel electrodes 191 is positionedthereon, and a pixel defining layer 360 positioned between adjacentpixels PX may be positioned thereon. The transistor layer TFL mayinclude a plurality of conductive layers, a semiconductor layer, aninsulating layer, and the like. For example, the transistor layer TFLmay have the same structure as the transistor layer TFL of the organiclight emitting diode (OLED) display according to the example embodimentillustrated in FIGS. 3 and 4 described above.

At least one layer of many insulating layers of the display elementlayer including the transistor layer TFL may extend even into theperipheral area PA to form a peripheral insulating layer INL.

The upper substrate 210 (e.g., the encapsulation substrate) ispositioned on or above the lower substrate 110 with the transistor layerTFL and the like, and the lower substrate 110 and the upper substrate210 are bonded to each other with the sealing body 310 in the peripheralarea PA. A distance D1 between the lower substrate 110 and the uppersubstrate 210 in the display area DA may be, for example, approximately6.2 μm, but is not limited thereto.

As described above, at least one of the right portion 310 a, the leftportion 310 b, the upper portion 310 c, and the lower portion 310 d ofthe sealing body 310 may have a different deposition structure from atleast one of the remaining portions.

Even in the example embodiment illustrated in FIGS. 9 to 12, during thebonding process of the lower substrate 110 and the upper substrate 210,when the sealant 311 is melted by applying heat, such as by a laser, tothe sealant 311, as an example, the heights of the sealants 311 at theleft portion 310 b and the upper portion 310 c may be greater than theheight of the right portion 310 a of the sealing body 310.

FIGS. 9 to 11 illustrate examples of deposition structures of the rightportion 310 a, the left portion 310 b, and the upper portion 310 c ofthe sealing body 310 in the peripheral area PA where the driver 500 isnot positioned, respectively. Even in the example embodiment, thedeposition structure of the right portion 310 a of the sealing body 310may be different from the deposition structures of the left portion 310b and the upper portion 310 c, and the deposition structures of the leftportion 310 b and the upper portion 310 c may be the same as each other.

Referring to FIG. 9, the right portion 310 a of the sealing body 310 mayinclude the sealant 311 and the first pattern 312. The sealant 311 mayinclude a frit and may bond the lower substrate 110 and the uppersubstrate 210 to each other. The first pattern 312, having an islandshape, may be positioned between the sealant 311 and the lower substrate110 and may include a conductive material such as a metal. In FIG. 9,the first pattern 312 is positioned above the peripheral insulatinglayer INL for convenience, but is not limited thereto, and the firstpattern 312 may be positioned in the peripheral insulating layer INL(e.g., in the middle of the peripheral insulating later INL) and mayalso be positioned therebelow. Further, in the case where the firstpattern 312 is formed as a multi-layer structure, the first pattern 312may be divided and positioned on several layers in the peripheralinsulating layer INL.

At the right portion 310 a, a height D5 of the sealant 311 may besubstantially the same as the distance D1 between the lower substrate110 and the upper substrate 210 in the display area DA.

According to another example embodiment of the present invention, theright portion 310 a of the sealing body 310 may also not include thefirst pattern 312 according to a desired or required thickness.

Referring to FIGS. 10 and 11, the left portion 310 b and the upperportion 310 c of the sealing body 310 may include a sealant 311 and athird pattern 315. As illustrated above, the left portion 310 b and theupper portion 310 c of the sealing body 310 may not include the firstpattern 312, and unlike this, may also include the first pattern 312according to a desired or required thickness.

Referring to FIG. 12, the third pattern 315 may include a plurality ofopenings formed by removing a part of the peripheral insulating layerINL. For example, the third pattern 315 may include an opening formed inat least one of the gate insulating layer 140, the first passivationlayer 180 a, and the second passivation layer 180 b according theexample embodiments described above.

The third pattern 315 may be concurrently (e.g., simultaneously) formedwhen the insulating layer of the display element layer of the displayarea DA is patterned. For example, when the peripheral insulating layerINL includes at least one of the gate insulating layer 140, the firstpassivation layer 180 a, and the second passivation layer 180 b, thethird pattern 315 may be concurrently (e.g., simultaneously) formed whena contact hole is formed in the insulating layer 140.

As such, when the openings are formed in the peripheral insulating layerINL, the height of the sealant 311 thereabove may be decreased dependingon a size (e.g., a depth) of the third pattern 315.

At the left portion 310 b and the upper portion 310 c of the sealingbody 310, a height D6 of the sealant 311 may be substantially the sameas the distance D1 between the lower substrate 110 and the uppersubstrate 210 in the display area DA.

As such, in the manufacturing process of the organic light emittingdiode (OLED) display, when a difference in height of the sealant 311occurs according to a position on the sealing body 310, the thirdpattern 315 may be further formed at a portion of the sealant 311 havinga relatively large height as described above to maintain a substantiallyuniform distance between the lower substrate 110 and the upper substrate210. In this case, the third pattern 315 may be concurrently (e.g.,simultaneously) formed when at least one of many insulating layers inthe display area DA is patterned, and by considering the height of thesealant 311, a kind and the number of insulating layers to be formedwith the third pattern 315 may be determined.

Next, the display device including the sealing body 310 according toanother example embodiment of the present invention will be describedwith reference to FIG. 13 together with the drawings described above.

FIG. 13 is a cross-sectional view of one edge of the display deviceaccording to the another example embodiment of the present invention.

Referring to FIG. 13, the display device according to the exampleembodiment of the present invention is similar to the example embodimentillustrated in FIGS. 6 to 8 and the example embodiment illustrated inFIGS. 9 to 11, described above, but the left portion 310 b and the upperportion 310 c of the sealing body 310 may be different. For example, theright portion 310 a of the sealing body 310 may include at least one ofthe first pattern 312 and the second pattern 313, but the left portion310 b and the upper portion 310 c of the sealing body 310 may notinclude any one of the first pattern 312 and the second pattern 313. Inthis case, at the left portion 310 b and the upper portion 310 c, aheight D6 of the sealant 311 may be substantially the same as thedistance D1 between the lower substrate 110 and the upper substrate 210in the display area DA.

In the several example embodiments illustrated in FIGS. 6 to 13described above, heights, volumes, or the like of the first pattern 312,the second pattern 313, and the third pattern 315 included in thesealing body 310 may be controlled (e.g., properly controlled) tomaintain a substantially uniform distance D1 between the lower substrate110 and the upper substrate 210 in the display area DA.

Next, a manufacturing method of a display device according to an exampleembodiment of the present invention will be described with reference toFIGS. 14 to 20.

FIGS. 14 to 20 are cross-sectional views illustrating intermediate actsof a manufacturing method of a display device according to an exampleembodiment of the present invention. Particularly, FIGS. 15 to 17 arecross-sectional views of the right portion 310 a of the sealing body310, and FIGS. 18 to 20 are cross-sectional views of the left portion310 b and the upper portion 310 c of the sealing body 310.

First, referring to FIG. 14, the lower substrate 110 and the uppersubstrate 210 are prepared, respectively.

Next, referring to FIGS. 15 and 18, a plurality of conductive layers, aninsulating layer, a semiconductor layer, and the like are laminated andpatterned on the lower substrate 110 to form a transistor layer TFL in adisplay area DA, to form a second pattern 313 and a first pattern 312 ina right region of a peripheral area PA, and to form the first pattern312 in left and upper regions of the peripheral area PA.

Next, referring to FIGS. 16 and 19, a plurality of pixel electrodes 191and a pixel defining layer 360 are formed on a transistor layer TFL ofthe display area DA, and a light emitting member and an opposedelectrode are formed thereon.

Next, referring to FIGS. 17 and 20, a sealant 311 is coated on theperipheral area PA of the lower substrate 110 or the upper substrate 210to surround the display area DA. Next, the lower substrate 110 and theupper substrate 210 are arranged and bonded to each other and then thesealant 311 is cured by applying heat to the sealant 311. In this case,the sealant 311 may be sequentially cured by irradiating a laser to thesealant 311. The laser may be irradiated along any one direction of thesealant 311 formed as a closed curve or rectangle, and in the exampleembodiment, for example, the laser is irradiated in a clockwisedirection or a counterclockwise direction from the right region of theperipheral area PA. In this case, the sealant 311 may be pushed (e.g.,may migrate) toward a region yet to be irradiated from a region that hasbeen irradiated and thus the height of the sealant 311 may be increasedalong the direction the laser is irradiated.

According to an example embodiment of the present invention, even thoughthe height of the sealant 311 may change according to a position on thesealing body 310, the second pattern 313 formed at a portion of thesealing body 310 having a smaller height is positioned below the sealant311, thereby compensating for a difference in height of the sealant 311and maintaining a substantially uniform distance between the lowersubstrate 110 and the upper substrate 210.

Next, a manufacturing method of a display device according to anotherexample embodiment of the present invention will be described withreference to FIGS. 21 to 24.

FIGS. 21 to 24 are cross-sectional views illustrating intermediate actsof a manufacturing method of a display device according to an exampleembodiment of the present invention. Particularly, FIGS. 21 and 22 arecross-sectional views of the right portion 310 a of the sealing body310, and FIGS. 23 and 24 are cross-sectional views of the left portion310 b and the upper portion 310 c of the sealing body 310.

First, referring to FIGS. 21 and 23, after the lower substrate 110 andthe upper substrate 210 are prepared, respectively, a plurality ofconductive layers, an insulating layer, a semiconductor layer, and thelike are laminated and patterned on the lower substrate 110 to form atransistor layer TFL in a display area DA. In this case, at least one ofvarious insulating layers of a display element layer including thetransistor layer TFL is formed in the peripheral area PA to form aperipheral insulating layer INL. Further, when the insulating layer ofthe transistor layer TFL is patterned, at least some layers of theperipheral insulating layer INL in the peripheral area PA may bepatterned together to form a third pattern 315 in the left and upperregions of the peripheral area PA. Further, a first pattern 312 may beformed in a right region of the peripheral area PA. As described above,the first pattern 312 may be positioned in the peripheral insulatinglayer INL (e.g., in the middle of the peripheral insulating layer INL),and may also be positioned therebelow. Further, in the case where thefirst pattern 312 is formed as a multi-layer structure, the firstpattern 312 may be divided and positioned on several layers in theperipheral insulating layer INL.

Next, referring to FIGS. 22 and 24, a plurality of pixel electrodes 191and a pixel defining layer 360 are formed on a transistor layer TFL ofthe display area DA, and a light emitting member and an opposedelectrode are formed thereon. Next, a sealant 311 is coated on theperipheral area PA of the lower substrate 110 or the upper substrate 210to substantially surround the display area DA. Next, the lower substrate110 and the upper substrate 210 are arranged and bonded to each otherand then the sealant 311 is cured by applying heat to the sealant 311.In this case, the sealant 311 may be sequentially cured by irradiating alaser to the sealant 311. The laser may be irradiated along any onedirection of the sealant 311 formed as a closed curve or rectangle, andin the example embodiment, for example, the laser is irradiated in aclockwise direction or a counterclockwise direction from the rightregion of the peripheral area PA. In this case, the sealant 311 may bepushed (e.g., may migrate) toward a region yet to be irradiated from aregion that has been irradiated and thus the height of the sealant 311may be increased along the direction the laser is irradiated.

According to an example embodiment of the present invention, even thoughthe height of the sealant 311 may be changed according to a position onthe sealing body 310, the third pattern 315 formed at a portion of thesealant body 310 having a greater height is positioned below the sealant311, thereby decreasing the height of the sealant 311 at that position,compensating for a difference in the height of the sealant 311 andmaintaining a substantially uniform distance between the lower substrate110 and the upper substrate 210.

While this invention has been described in connection with what ispresently considered to be practical example embodiments, it is to beunderstood that the invention is not limited to the disclosedembodiments, but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims and their equivalents.

Description of symbols 110: Lower substrate 121: Scanning signal line140: Gate insulating layer 171: Data line 172: Driving voltage line180a, 180b: Passivation layer 191: Pixel electrode 210: Upper substrate270: Opposed electrode 310: Sealing body 311: Sealant 312: First pattern313: Second pattern 315: Third pattern 360: Pixel defining layer 370:Light emitting member 500: Driver

What is claimed is:
 1. A display device, comprising: a lower substrate;an upper substrate facing the lower substrate; a display element layerin a display area of the lower substrate and comprising a thin filmtransistor; and a sealing body in a peripheral area surrounding thedisplay area, having a closed curve shape, and between the lowersubstrate and the upper substrate, wherein the sealing body comprises afirst portion and a second portion, the first portion and the secondportion respectively extending along different directions from eachother, and the first portion and the second portion respectively havedifferent deposition structures from each other.
 2. The display deviceof claim 1, wherein: the sealing body comprises a sealant coupling thelower substrate and the upper substrate, and the sealant at the firstportion and the sealant at the second portion are different in heightfrom each other.
 3. The display device of claim 2, wherein: the firstportion comprises a first pattern, and the second portion does notcomprise the first pattern.
 4. The display device of claim 3, wherein:the first pattern comprises a pattern that is at least one layer of thedisplay element layer.
 5. The display device of claim 4, wherein: thefirst pattern further comprises a layer that is at least one of aconductive layer, a semiconductor layer, and an insulating layer, andthe conductive layer, the semiconductor layer, and the insulating layerare in the display element layer.
 6. The display device of claim 5,wherein: a the sealant at the first portion is less in height than thatof the sealant at the second portion.
 7. The display device of claim 6,wherein: the first portion and the second portion each further comprisea second pattern comprising a metal.
 8. The display device of claim 7,wherein: the sealant comprises a frit.
 9. The display device of claim 4,further comprising: a peripheral insulating layer between the sealantand the lower substrate wherein, the peripheral insulating layer is atleast one insulating layer of the display element layer, and the firstpattern comprises an opening in the peripheral insulating layer.
 10. Thedisplay device of claim 9, wherein: the second portion further comprisesa second pattern comprising a metal.
 11. The display device of claim 10,wherein: the sealant comprises a frit.
 12. A manufacturing method of adisplay device, the method comprising: providing a lower substrate andan upper substrate that include a display area and a peripheral areaaround the display area; and forming a sealing body between the lowersubstrate and the upper substrate, the sealing body having a closedcurve shape surrounding the display area and positioned in theperipheral area, wherein the sealing body comprises a first portion anda second portion, the first portion and the second portion respectivelyextending along different directions from each other, and the firstportion and the second portion respectively have different depositionstructures from each other.
 13. The manufacturing method of a displaydevice of claim 12, wherein: the forming of the sealing body comprisescoating a sealant to couple the lower substrate and the upper substratewith each other on the lower substrate or the upper substrate, andcuring the sealant, wherein the cured sealant at the first portion andthe cured sealant at the second portion are different in height fromeach other.
 14. The manufacturing method of a display device of claim13, wherein: the forming of the sealing body further comprises forming afirst pattern in the first portion but not in the second portion. 15.The manufacturing method of a display device of claim 14, furthercomprising: forming a display element layer comprising a thin filmtransistor in the display area of the lower substrate, wherein the firstpattern is formed utilizing a same process as at least one layer of thedisplay element layer.
 16. The manufacturing method of a display deviceof claim 15, wherein: the first pattern comprises a layer that is atleast one of a conductive layer, a semiconductor layer, and aninsulating layer, and the conductive layer, the semiconductor layer, andthe insulating layer are in the display element layer.
 17. Themanufacturing method of a display device of claim 16, wherein: after thecuring of the sealant, the sealant at the first portion is less inheight than that of the sealant at the second portion.
 18. Themanufacturing method of a display device of claim 15, wherein: theforming of the display element layer comprises forming a peripheralinsulating layer between the sealant and the lower substrate, theperipheral insulating layer is at least one insulating layer of thedisplay element layer, and the first pattern has an opening in theperipheral insulating layer.
 19. The manufacturing method of a displaydevice of claim 18, wherein: the first pattern is formed when the atleast one insulating layer of the display element layer is patterned.20. The manufacturing method of a display device of claim 13, wherein:the sealant comprises a frit.